Safety pulley shackle



y 3951 w. R. LEO'NARD 2,551,803

SAFETY PULLEY SHACKLE Filed June 19, 1947 [N VEN TOR.

BY lama? /Z. ATTOK/Vf) Patented May 8, 1951 UNITED STATES OFFlCE 1 Claim.

This invention relates to an improved safety shackle particularly intended for use in connection with the pulley blocks employed in logging operations, and is applicable in any instance where a wire rope strap is used to secure a pulley block; to any object, such as a spar tree, spar stump, log boom, or the like.

Under prevalent practice, a wire rope strap having eyes at both ends is employed, and in order to form said eyes, about four feet of the cable at each end thereof is looped back to overlap the intermediate portion of the strap and secured to form said eyes. Thus, for instance, sixteen feet of cable is necessary to provide a strap only eight feet in effective length. Moreover, frequently recurring intermittent strain on the eyes causes the wire thereof to soon crystallize, with the result that the straps last only a short time.

The objects of the present invention, therefore, are to provide shackle wherein knobs will he used on the ends of a length of cable to form a strap, thus effecting a saving in the length of cable necessary to provide a strap of any given lineal dimension as well as avoiding crystal1ization of the cable as recurringly experienced in connection with the eyes of conventional straps, wherein the shackle block will be formed to accommodate said knobs, securely anchoring the strap to the block, wherein the strap may be readily attached to or detached from the block, when so desired, wherein the knobs will be locked against accidental detachment from the shackle block by the conventional pulley block of the line or cable anchored by the shackle, and wherein the single pin employed to connect the line block with the shackle block will serve to detachably secure all of the parts in assembled relation.

Other and incidental objects of the invention will appear during the course of the following description, and in the drawings:

Figure 1 is a perspective view showing the shackle employed to anchor a conventional line block to a spar tree.

Fi ure 2 is a perspective view of the shackle block.

Figure 3 is a horizontal section on the line 33 of Figure 2 and showing the ends of the rope strap.

T'gure 4 is a vertical section on the line 4-4 of In carrying the invention into eifect, I ema shackle bloom-indicated as a whole at it. shackle block may be formed of steel, or other approved material, and includes a flat head plate a 5, parallel cheek plates l2, and end plates I M is extending between the cheek plates at the ends of the head plate, the block preferably being a unitary structure. Formed in the head plate 7 i l medially thereof is a longitudinal slot It midway between the ends of which the walls of the slot are cutaway to provide a circular opening l5.

In conjunction with the block it, I provide a removable pin it. This pin extends freely through the free marginal portions of the cheek plates 12 medially thereof and is provided at one end with a head ll, while near its opposite end, the pin is formed to removably receive a cotter key it detachably securing the pin in position.

I further employ a rope strap l9 which is formed of a suitable length of wire cable of appropriate diameter. Securely fixed to the ends of said strap in any approved manner are cylindrical metal knobs Z8, and, as will be appreciated, these knobs supplant the usual looped eyes of conventional rope straps with a resultant economy in the length of cable necessary to provide a strap of any given lineal dimension. The knobs 26 are of a diameter to pass freely through the opening it; of the block l0.

In the drawings, I have shown my improved shackle anchored to a spar tree 2!, and have shown a conventional pulley block 22 connected to the shackle, said block being provided with the usual eye 23. A so-ca-lled high line '24 is shown as trained through the pulley block. It would appear unnecessary to enter into a description of the various lines, pulleys, and other equipment commonly employed, or the particular function of each part, as such outfits are well known.

in use, the strap i9 is looped about the spar tree 2i, when the knobs 29, first one and then the other, are inserted through the opening l5 of the shackle block it! and moved to the ends of the slot M, the end walls of the slot being adapted to limit spreading of the ends of the strap. The eye 23 of the pulley block 22 is then inserted between the cheek plates [2 of the block m, when the pin it is installed to extend through said eye, pivotally connecting the pulley block with the shackle block. Thus, the knobs 20 of the strap it will abut the inner face of the head .late 5 l of the shackle block In so that the strap will serve to anchor the assembly to the spar tree.

It is now to be noted that the inner end faces of the knobs 25 are preferably beveled so that said knobs may sit flat against the inner face of the head plate H of the shackle block it? at an angle more or less conforming to the divergent angularity of the end portions of the strap I9. Undue bending of the end portions of the strap,

under strain, will thus be avoided and, of course, the inner ends of the knobs may be beveled at any chosen angle.

It is further to be noted that the eye 23 of the pulley block 22 is so connected with the shackle block I!) that said eye projects between the knobs 20 of the strap 19. The eye thus blocks movement of the knobs into registry with the opening 15 of the shackle block and serves to prevent accidental release of said knobs. However, by removing the single pin I6, the parts may, as will be seen, be readily detached from each other. The pin thus serves not only in its function to pivotally connect the pulley block 22 with the shackle block 40, but also the added function of a key locking all of the parts in assembled relation.

In any instance where it is desired to anchor the device to a stump or the like, the mode of assembly of the device i somewhat different from that above described for connecting the device with a tree. When it is desired to connect the device with a stump, for instance, quick and easy assembly of the device is accomplished by flexing the strap 19 to form a loop, when the bight of the loop is inserted between the cheek plates l2 of the shackle block IE to project through the slot M of the head plate H, after which the block is shifted forwardly along the end portions of the strap until the knobs 20 seat against the forward side of the head plate. Thus, both ends of the strap are simultaneously connected with the shackle block l8, following which the loop formed by the strap may be dropped over the stump for anchoring the device thereto. It will be noted that after the bight of the loop of the strap 19 is first inserted through the slot I l, as just above outlined, the shackle block Ill will restrain the end portions of the strap against spreading movement neither end of the strap may slip free to thrash about and possibly injure a workman.

Assuming the device to be connected to a tree, as shown in Figure 1 of the drawings, or connected to a stump, as just above described, it will be observed, as best brought out in Figure 3, that the slot I in the head plate ll of the shackle block 10 provides an open space between the ends of the strap [9. Also, it will be noted that when forward strain i exerted on the pulley block 22,

so that -c the end portions of said strap will tend to straighten and thus flex in a direction away from the end walls of the slot. Consequently, the ends of the strap will not be tensioned across any abrupt angles of the shackle block to abrade or otherwise injure the wire cable of the strap.

Having thus described my invention, I claim: A pulley shackle including a shackle block having spaced confronting cheek plates connected at their rear ends by an oblong head plate provided with a longitudinal slot having end walls and side walls, the side walls of the slot being cut away medially of said slot to provide an opening, a rope strap having end portions connected by an intermediate portion adapted to be inserted between the forward ends of said cheek plates and moved rearwardly therebteween through said slot to extend at the rear of the block supporting the end portions of the strap to extend side by side transversely through said slot limited against movement into alignment with each other by the end walls of said slot, and kncbs carried by the ends of said strap and of a major thickness greater than the width of said slot to engage the forward side of said head plate detachably connecting the end portions of the strap with the shackle block, said knobs being seiectr-ely movable into registry with said opening and being adapted to be selectively withdrawn therethrough for detaching first one end portion of the strap and then the other end portion thereof rearwardly from the block and both end portions of the strap being simultaneously movable forwardly side by side to draw the intermediate portion of the strap forwardly through said slot between the cheek plates for detaching the strap forwardly from the block.

\VILLIAM R. LEONARD.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS I Number Name Date 686,829 McEwen Nov. 19, 1901 1,225,100 Aubrey May 8, 1917 1,429,110 Seavey Sept. 12, 1922 2,204,211 Forrester June 11, 1940 2,406,607 Jensen Aug. 27, 1946 

